Which one of the following terms describes not only the physical space occupied by an organism, but also its functional role in the community of organisms?

• (a) Ecotone: It is a transition zone between two ecosystems or communities, not the role of a species. Verdict: Incorrect.
• (b) Ecological niche: A niche includes both the place of an organism and its functional role in the ecosystem—how it uses resources and interacts with others. Verdict: Correct.
• (c) Habitat: Habitat means the physical place where an organism lives, but it does not fully capture its functional role. Verdict: Incorrect.
• (d) Home range: Home range is the area an animal regularly moves through for feeding, mating, etc.; it is not its ecological role. Verdict: Incorrect.

Answer: (b) Ecological niche.